Electrostatic charge eliminator combined with a tufting machine



ELECTROSTA'iIC CHARGE ELIMINATOR COMBINED WITH A TUFTING MACHINE Filed Dec. 10, 1964 Jan. 17, 1967 G ED ORD ET AL 3,298,340

o-ro'oo'oooo iooooooooo United States Patent tries, Inc., Greensboro, NC, a corporation of Delaware Filed Dec. 10, 1964, Ser. No. 417,353 3 Claims. (Cl. 112-79) This invention relates to pile fabric tufting equipment and more particularly to an improved pile fabric tufting machine having means for eliminating electrostatic charges in the needle zone.

Pile fabrics of the type referred to herein are primarily used for soft floor coverings and are manufactured on tufting machines having a series of vertically reciprocating needles to which the yarns are fed from creels. These machines range all the way from single needle table machines to yardage machines which are capable of producing fabrics feet or more in width and may have as many as 1500 needles. The individual yarn ends are fed from the creel through various guides and thence through tubes to a point over the tufting machine which may or may not be equipped with so-called pattern attachments for controlling the amount and/or tension in the various yarn ends to provide patterned goods.

In the tufting of certain yarns it has been found that the presence of a static charge in the area of the tufting needles and/ or jerker bar causes certain of the individual yarn filaments to gather or bunch at the eyes of the needles. At first the cause of this condition was not apparent. It was theorized that the needle eyes might be too small or insufficiently smooth, or possibly that improper yarn tensions caused bunched filaments and ultimate yarn breakage at the needles. After considerable experimentation it was found that this problem in certain yarns could be eliminated or substantially reduced by the incorporation of a device for the tufting machine positioned closely adjacent the needles which would eliminate electrostatic charges developed in the yarns in the area of the stationary yarn guide and/ or the jerker bar.

A primary object of the invention therefore is to provide a tufting machine capable of tufting certain types of synthetic yarns, either staple or monofilament, under conditions which would otherwise produce substantial malfunctioning of the equipment because of fiber filaments bunching at the needles.

A further object of the invention is to provide means for eliminating electrostatic charges on the synthetic yarns of a tufting machine while the yarns are being tufted through a backing fabric.

A further object of the invention is to provide means for eliminating electrostatic charges on the synthetic yarns of a tufting machine at the stationary yarn guide im mediately above the jerker bar.

And a further object of the invention is to provide means for eliminating electrostatic charges in the pile yarn at the jerker bar of a multi-needle pile tufting machine.

Further objects will be apparent from the specification and drawings in which FIGURE 1 is a transverse section of a multi-needle pile tufting machine incorporating the present invention in a zone slightly removed from the tufting needles,

FIGURE 2 is a schematic perspective of the apparatus of FIGURE 1 showing the mounting for one of the stationary yarn guides,

FIGURE 3 is an enlarged sectional detail as seen at 33 of FIGURE 2,

FIGURE 4 is an enlarged sectional detail showing the jerker bar provided with an insulated mounting for eliminating static charges,

FIGURE 5 is an enlarged sectional detail as seen at 55 of FIGURE 4, and

FIGURE 6 is a wiring diagram of the electric circuits and transformer shown in FIGURE 2.

Referring now more particularly to the drawings, a conventional multi-needle pile tufting machine is provided with a frame or bed 15 over which the fabric F is drawn by means of pin takeup roll 16 and pin feed roll 17. As the backing fabric F passes over the throat 18 a series of needles 19, 19 mounted in vertically reciprocating needle bar 20 carry pile yarns into and through the fabric F where the yarns form a series of loops L engaged by the loopers 21 mounted in looper holders 22 secured to looper rockshaft 23. The needle bar 20 is reciprocated by means of connecting rods 25 journaled in bushings 26 and secured at their upper ends to a pair of cranks 27, only one of which is shown, connected to crankshaft 28. The crankshaft 28 and the cranks 27 are enclosed in a suitable housing 30 and the lower part of the housing carries presser foot 31 suspended therefrom by means of brackets 32, 32.

The pile yarns P are drawn from a conventional yarn supply which may be a creel or beam and pass through a first stationary yarn guide 35, and a second stationary yarn guide bar 36 supported on housing 30 by means of a series of brackets 37, 37 and cap screws 38, 38. The pile yarns then pass through a yarn guide 40 which is mounted on the needle bar 20 and is customarily termed a yarn jerker or jerker bar. The yarns then pass directly to the eyes in needles 19 by means of which they are inserted through the backing fabric.

In FIGURES l and 2 stationary yarn guide 36 and brackets 37, one of which is shown in FIGURE 2, are supported on the housing 30 by means of insulating blocks or spacers 43 and 44 so that there is no electrical contact or connection between the yarn guide 36 and the frame of the tufting machine. At one end of the stationary yarn guide 36 we connect an electrical lead 45 which is in turn connected to a transformer 46 capable of being energized when connected to the tufting machine current supply by means of leads 47, 48. The transformer 46 generates a controlled high voltage which is applied in the stationary yarn guide area and which effectively eliminates any electrostatic charge present on the yarn ends in this zone. If desired the jerker bar 40 may be insulated from the remainder of the tufting machine as shown in FIG- URES 4 and 5 by means of dielectric spacers 50, 51 to which the brackets 52 supporting the jerker bar 40 are secured. An insulating bushing 53 (FIGURE 5) is employed to complete the mounting of the jerker bar 40. Lead 45 in this instance is secured to one end of the jerker bar in the same manner as shown in FIGURE 2. If desired a second transformer may be utilized to create a high voltage at the jerker bar in addition to the voltage equipment 45 and 46 on the stationary yarn guide.

A preferred form of electrical connection for the transformer assembly 46 is shown in FIGURE 6 in which the transformer proper 46a has its primary winding connected to the main current source 55 or to leads on the tufting machine motor starter 56 as shown. The amount of current in the primary winding or transformer 46a may be regulated by a suitable ballast 57 such as an ordinary incandescent lamp. This current may be varied by using various wattage bulbs as desired. A relay 58 is incorporated to insure that there will be no charge on the yarn guide 36 or the jerker bar when the machine is stopped. Such a charge would be undesirable from the operators standpoint when threading the needles or repairing broken ends. A suitable resistance 59 may be incorporated in the transformer assembly as shown. In some instances satisfactory results can be achieved simply by creating high voltage zone at the stationary guide thus avoiding the high 3 speed flexing of cable 45. Where conditions are such that a second high voltage zone is indicated, the jerker bar mounting may be utilized and this has the advantage of eliminating any static charge at the point closest to the needles themselves.

It will be understood that we have discovered the reasons why certain types of synthetic yarns give difliculty in running through a tufting machine. We have also provided simple and inexpensive means for overcoming problems which in the past were not attributed to the presence of an electrostatic charge in this particular area.

Having thus described our invention, we claim:

1. In apparatus for tufting pile fabrics and the like, the combination which comprises a needle bar, means for oscillating said needle bar, a series of needles mounted in the needle bar for carrying pile yarns through a backing fabric, means for advancing the backing fabric underneath said needles, a source of pile yarns, guide means through which the yarns are fed in contact with said guide means from the yarn source to the needles, an electrically insulated mounting for said guide means, a high voltage A.C. transformer electrically connected to said guide means to impart an electrical charge on the guide means to counteract an induced D.C. electrostatic charge in the 7 area of the guide means, electrical connections for connecting said transformer to a power source, and relay means interconnected between the transformer and the power source to open the circuit to the transformer when the means for oscillating the needle bar is inoperative.

2. Apparatus in accordance with claim 1 in which the yarn guide means is fixed.

3. Apparatus in accordance with claim 1 in which the yarn guide means is mounted on the needle bar.

References Cited by the Examiner UNITED STATES PATENTS JORDAN FRANKLIN, Primary Examiner.

I. R. BOLER, Assistant Examiner. 

1. IN APPARATUS FOR TUFTING PILE FABRICS AND THE LIKE, THE COMBINATION WHICH COMPRISES A NEEDLE BAR, MEANS FOR OSCILLATING SAID NEEDLE BAR, A SERIES OF NEEDLES MOUNTED IN THE NEEDLE BAR FOR CARRYING PILE YARNS THROUGH A BACKING FABRIC, MEANS FOR ADVANCING THE BACKING FABRIC UNDERNEATH SAID NEEDLES, A SOURCE OF PILE YARNS, GUIDE MEANS THROUGH WHICH THE YARNS ARE FED IN CONTACT WITH SAID GUIDE MEANS FROM THE YARN SOURCE TO THE NEEDLES, AN ELECTRICALLY INSULATED MOUNTING FOR SAID GUIDE MEANS, A HIGH VOLTAGE A.C. TRANSFORMER ELECTRICALLY CONNECTED TO SAID GUIDE MEANS TO IMPART AN ELECTRICAL CHARGE ON THE GUIDE MEANS TO COUNTERACT AN INDUCED D.C. ELECTROSTATIC CHARGE IN THE AREA OF THE GUIDE MEANS, ELECTRICAL CONNECTIONS FOR CONNECTING SAID TRANSFORMER TO A POWER SOURCE, AND RELAY MEANS INTERCONNECTED BETWEEN THE TRNSFORMER AND THE POWER SOURCE TO OPEN THE CIRCUIT TO THE TRANSFORMER WHEN THE MEANS FOR OSCILLATING THE NEEDLE BAR IS INOPERATIVE. 